The present invention relates to an actuating arrangement for several throttle valves belonging preferably to a structural group of a suction pipe of a multi-cylinder internal combustion engine, whereby the throttle valves to be actuated synchronously are connected with their bearing shafts to levers extending outside of the suction pipe, and the bearing shafts cooperate with a common linkage.
In a known internal combustion engine (DE-GM No. 19 86 850), two separate suction pipes are led to a cylinder which includes two inlet valves. Both suction pipes are provided with throttle valves which are adjusted independently of one another.
It is the object of the present invention to undertake such measures in an actuating arrangement of several suction pipe-throttle valves of a multi-cylinder internal combustion engine, which are to be synchronously actuated, that the actuating arrangement can be easily installed and customary tolerances which always result between individual throttle valves are compensated without special adjusting operations.
The underlying problems are solved according to the present invention in that yielding members are provided between the linkage and the bearing shafts of the throttle valves and a device stressing the throttle valves into their closed end positions by means of the levers engages at the linkage.
The principal advantages obtainable with the present invention reside in that customary tolerances which could be reduced only with an unacceptably high expenditure are compensated by the elastic elements and the device stressing the throttle valves into their closed end position. It is assured thereby that in the closed position of the throttle valves no medium--fuel-air-mixture--reaches the combustion space by way of the mentioned valves. This is of particular significance in internal combustion engines with two inlet valves and two separate suction pipe sections per cylinder, of which at least one of these sections is provided with a throttle valve adapted to be turned on and off. The possibility exists with this type of suction pipe construction to considerably improve the torque curve of the internal combustion engine at low and middle rotational speeds.
The elastic or yielding members can be formed in a simple manner by rotationally elastic bearings which are coordinated to the levers. By means of the single actuating rod, not only the structural expenditure is reduced, but also the assembly and adjusting operation of the actuating mechanism is facilitated.